1. Field of the Invention
The present invention relates to a ski with a variable inertia moment. More specifically, since the behavior of a ski in motion depends, among other things, essentially on the inertia moment which the ski opposes to a change in the direction of movement, the present invention provides a ski with which it is possible, when desired or necessary, to adapt the inertia moment thereof to the given circumstances.
2. Description of the Prior Art
From DT-PS West German Pat. No. 2,052,332 to Ernst Werner Gunzel, filed Oct. 24, 1970 and published Jan. 29, 1976, a ski is known on which weights disposed on or inside the rear or front part thereof can be moved in the longitudinal direction of the ski, and fixed, to change its inertia moment. By altering the distance of the weights from either end of the ski, its inertia moment is changed around both a vertical or rotation axis of the ski and a horizontal axis oblique to the longitudinal direction of the ski. The inertia moment around the vertical or rotation axis influences the "rotation behavior" of the ski. Thus, a ski with a small inertia moment, e.g., a short ski or a ski especially light at the ends, can be rotated more easily than a ski with a large inertia moment. An easily rotated ski is especially suitable for particular snow conditions such as deep or heavy snow, terrain conditions, such as a bumpy run, and skiing abilities such as, beginners or in trick skiing, A ski with a large inertia moment, that is a long ski or a ski with relatively large weights at the ends, has exceptional directional stability during fast downhill runs because the forces exerted horizontally on the ski by the inequalities of the slope, especially on traversing laterally, are "swallowed" better because of the larger inertia moment of the ski.
The inertia moment around an axis oblique to the longitudinal direction of the ski determines the elastic properties of the front or rear part of the ski at any given time. When travelling rapidly, vertical changes in direction are conveyed to the ski, especially the front part, by the inequalities of the slope. A greater weight at this point on the ski effects a greater smoothness of running and prevents "wobbling". In this way, better holding of the ground by the ski edges and thus good directional stability are obtained.
However, the practical execution of this system was very difficult and expensive. The arrangement of the weights inside the ski unfavorably weakened the cross-section of the ski and required the construction of completely new skis with hollow cross sections and adjustment mechanisms. With the weights arranged on the surface of the ski, the functioning of the adjustment mechanism is liable to be impaired by deposits of snow and ice and other mechanical influences such as occur, for example, when the skis are crossed or on falling. The fact that the weights and thus the weight of the ski remain the same when the inertia moment is decreased, by shifting the weights in the direction of the middle of the ski, is also disadvantageous.